1. Field of the Invention
The present invention relates generally to distributed control digital communication systems and more particularly to the provision for broadcasting of information from a source to a plurality of destinations in such systems. The present invention also relates to the provision of a conferencing capability between a plurality of terminals in such a system and to the provision of a plurality of such conferences within the overall communication system. The present invention is particularly applicable to the field of telephony.
2. Description of the Prior Art
Conventional telephone exchanges arrange for multiparty conferencing conversation by providing one conferencing bridge for each subscriber connected to the network. The conference signals must be routed to a conference circuit that incorporates the conference bridge and is generally extraneous to the network that makes the standard interconnections, i.e. for two-party telephone calls. The conference bridge, therefore, requires speech paths in addition to the number of paths required to complete two-party connections; first, to carry the speech signals from the network to the bridge and, second, from the bridge to the network.
Although the conference circuit and bridge provided allow conference calls to be completed among any group of subscribers, the cost of the additional circuitry and of the bridges themselves is substantial and requires additional space for this equipment at the switching facility than otherwise would be required.